Not applicable.
Not applicable.
This invention relates to telescoping covers and in particular to a bumper of a telescoping cover which absorbs the impact between adjacent cover sections upon extension and retraction of the cover.
Telescoping covers, such as the telescoping machine tool way covers shown in FIGS. 1-3, are typically made of a number of sheet metal sections which are telescoped together. The sections have end walls or flanges that catch on one another so that when one end of the cover is pulled away from the opposite end of the cover, the cover expands by one of the end walls or flanges of one of the sections abutting the end wall or flange of the next adjacent section. Similarly, when retracting, the end walls or flanges of the way sections abut the end walls or flanges of the adjacent way sections until the way cover is totally collapsed.
Some sort of bumpers have normally been used to dampen the impact as one way cover section bumps into another. These bumpers have typically been elastomeric pads which are placed between the abutting walls of adjacent way cover sections.
While they have been somewhat effective, the spring rate of them has generally been either too soft or too stiff. Also, as they have typically been molded elastomeric compound, they have been prone to deterioration from repetitive use and attack by the oils and chemicals. Others have been simply adhered to the walls of the sections and have been prone to falling off which can jam the way cover since if it falls off on one side but not the other, it can become skewed, requiring expensive downtime of the machine tool.
The present invention provides a bumper with a spring rate and dampening capability adapted for a way cover which is dog-bone shaped and made of an elastomeric material which is held on a flange of a way cover section so that it straddles the flange, extending from each side of the flange. The bumper is dog-bone shaped to provide a combination of flexing and compression to yield a soft start from flexing of the ends of the bumper and provide faster acceleration of the cover sections beyond the flexing limit of the bumper.
Two or more such bumpers, each of a uniform thickness, are preferably provided on each flange.
In addition, since the bumper is made of an elastomeric material, it can be made with mounting holes which can be expanded over mounting projections of the flange so as to hold the bumper mechanically straddling the flange. Such a bumper provides a progressive spring rate to dampen the acceleration forces that occur when one section bumps into another and which is durable, easily assembled and largely trouble-free in use.
The foregoing and other objects and advantages of the invention will appear in the detailed description which follows. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention.